Generalized Lomb–Scargle periodograms (GLS) of the EPIC 246471491 RVs from CARMENES data (panel a), the K2 photometry (panel b), and the CRX (panel c), dLW (panel d), FWHM (panel e), CTR (panel f), and BVS (panel g) indices. Panel h: window function of the data. Vertical red lines indicate the frequencies associated with each of the four transiting planets, and the blue vertical lines mark the frequencies associated with the activity of the host star. The highest peaks in the CARMENES GLS are located at f = 0.045 d⁻¹ (P ~ 22 d) and f = 0.081 d⁻¹ (P = 12.1 d) and are linked to the rotation of the star. These periodicities are also significant in the K2 photometry and the CRX index. Horizontal lines show the FAP levels of 10% (short-dashed line), 1% (long-dashed line) and 0.1% (dot-dashed line).